Radar is frequently used in collision avoidance systems, being used to detect collision hazards such as other vehicles. In Doppler radar, a frequency shift due to relative motion of the target is detected. However, the resolution of a conventional continuous-wave Doppler system is typically too low to reliably detect the motion of slow moving obstacles, such as pedestrians. Hence, an improved Doppler collision avoidance radar would find uses in many applications, such as improved vehicular collision avoidance systems.